Evaluation and Development of Osmotic Drug Delivery of Venlafaxine Hydrochloride Tablet

Osmotic systems utilizes the principle of osmosis for delivery of drug. It is advantageous that drug release from the osmotic devices independent of physiological environment and pH. Drug release can be optimized to zero order release rate by modifying formulation properties. Venlafaxine Hydrochloride(VH), an antidepressant agent structurally unrelated to other antidepressants, is used to treat melancholia, generalized anxiety disorder (GAD), panic disorder, post-traumatic stress disorder, and hot flashes in breast cancer survivors. Absolute bioavailability is 45% and a single oral dose is well absorbed (at least 92%). Depressive illness generally requires long duration of drug therapy and plasma concentration substantially need to remain constant for better tolerability. Compared to Venlafaxine immediate release (IR) dosage form extended release dosage forms (ER) are well tolerated. Venlafaxine hydrochloride is highly water soluble drug(570mg/ml), so incorporation of release retardant polymers may modify release pattern for longer duration of release. Hence, it was decided to formulate CPOP of venlafaxine hydrochloride using release retardant hydrophilic polymers.